1. Field of the Invention
The present invention relates to an end face polishing apparatus for polishing end faces of rod-shaped members of optical communication fibers and the like.
2. Description of the Related Art
An optical communication fiber is used after it has been adhered and fixed to a center hole of a ferrule which is a main member of a connector, and then an end surface of the ferrule and an end surface of the fiber are simultaneously polished to provide a smooth mirror surface. If the polished surfaces of the ferrule and the fiber thus polished are not vertical to a center axis of the ferrule, or the polished surfaces are damaged, the accuracy of an optical connector having such ferrules connected with each other is deteriorated, thereby resulting in an increase in signal loss. Therefore, the polished surface of a ferrule including an optical fiber requires finishing of the polished surface with high accuracy.
Japanese Patent Application Laid-open No. 3-26456 discloses a conventional optical fiber end face polishing apparatus. The optical fiber end face polishing apparatus disclosed in this publication has an eccentric plate which rotates on a concentric circle of a self-rotation disc, and has a planetary gear which transmits rotation of a motor for revolution to this eccentric plate, and these are combined with a polishing plate to cause the polishing plate to self-rotate and revolve. The end-faces of the ferrules supported by a jig plate are pressed against the polishing member fixed to the polishing plate and polished.
As described above, the conventional optical fiber end-face polishing apparatus conducts a polishing operation by pressing with a spring the end faces of a plurality of ferrules, such as rod-shaped members, supported by the jig plate against the polishing member fixed to the rotating and revolving polishing plate. However, polishing of the rod-shaped members is adjusted by time, so that the polishing length of the rod-shaped members cannot be adjusted. Further, there is no problem if the lengths of the ferrules mounted on the jig plate are all the same, however, since adhesives for fixing the ferrule and the optical fiber together flow out from the tip end of the ferrule and harden, the lengths of the respective ferrules differ. Therefore, if the ferrules differing in lengths are made to slidable contact the polishing plate, the jig plate tilts relative to the polishing plate, thereby causing variations in the polishing angle, radius of curvature and eccentricity. Further variations in ferrule lengths also occur after polishing.
It is an object of the present invention to provide an end face polishing apparatus with improved polishing accuracy regardless of the length of the ferrule when polishing the end faces of the ferrule.
According to a first aspect of the present invention, an end face polishing apparatus has a jig plate for supporting a rod-shaped member, a polishing member, a polishing member mounted on a polishing plate for polishing an end face of the rod-shaped member, and an apparatus body for rotationally and pivotally supporting the polishing plate. A slidable contact member is provided on one of the jig plate and the polishing plate for contacting the other of the jig plate and the polishing plate with low friction.
According to a second aspect of the present invention, the length in the axial direction of the rod-shaped member protruding form the lower end face of the jig plate is longer than the height of the slidable contact member.
According to a third aspect of the present invention, the jig plate is biased against the polishing plate by an apparatus body of a support mechanism.
According to a fourth aspect of the present invention, the jig plate comprises an adjusting mechanism for adjusting the height of the polishing member.
According to the end face polishing apparatus of the present invention, by providing a slidable contact portion on either the jig plate or the polishing plate to slidably contact the other with low friction, the jig plate can be maintained horizontal to the polishing plate, thereby improving the polishing accuracy of the rod-shaped member. Further, the length of the rod-shaped members may be made uniform.